CN110975795A

CN110975795A - Synthesis method of lithium extraction adsorbent

Info

Publication number: CN110975795A
Application number: CN201911323242.3A
Authority: CN
Inventors: 杨刚; 仵档; 孙朋飞
Original assignee: Jiangsu Liboxing Water Technology Co ltd; Nanjing Tech University
Current assignee: Jiangsu Liboxing Water Technology Co ltd; Nanjing Tech University
Priority date: 2019-12-20
Filing date: 2019-12-20
Publication date: 2020-04-10

Abstract

The invention discloses a synthesis method of a lithium extraction adsorbent, which comprises the steps of dissolving a lithium source in a solvent containing a certain amount of additives, adding a titanium source into the solvent to uniformly mix the lithium source and the solvent to form a solid-liquid mixed state, performing drying treatment to assist synthesis, drying the raw materials quickly, mixing the raw materials fully, and calcining the raw materials to obtain a lithium ion sieve precursor Li with uniformly distributed particle sizes₂TiO₃(ii) a Precursor Li₂TiO₃Metatitanic acid type lithium ion sieve H obtained after acid elution of lithium₂TiO₃Has obvious adsorption effect. The invention is simple and easy to implement, and the lithium ion sieve H₂TiO₃The method is mainly used for extracting lithium from water bodies such as salt lake brine, oil field brine, seawater and the like, and has great potential in the aspect of liquid lithium extraction.

Description

Synthesis method of lithium extraction adsorbent

Technical Field

The invention relates to the technical field of adsorption materials, and particularly relates to a synthesis method of a lithium extraction adsorbent.

Background

Lithium is closely related to human life, and lithium is an alkali metal with the smallest atomic radius and is also the lightest metal known at present. It is known as an energy material and strategic resource and has a wide range of applications in many areas like glass, ceramics, pharmaceuticals, aerospace vehicles, nuclear industry and the best known lithium battery industry. Especially, in recent years, the demand for lithium resources has been increasing.

The total amount of lithium resources in China is the fourth world and accounts for about 13.21% of the total amount of lithium stored in the world. However, over 79% of the lithium resources in China exist in salt lake brine and oil field underground brine in a liquid state. The ore lithium resource is gradually reduced along with the exploitation, and the demand of lithium at present and in the future is far from being met. Therefore, one focuses on the extraction of lithium resources from liquids. However, the content of magnesium in the salt lake brine in China is high, when the ratio of magnesium to lithium reaches 20, lithium is defined as difficult to extract, and the ratio of magnesium to lithium in some salt lakes in China is even as high as 500.

There are many methods for extracting lithium from liquids, such as evaporative crystallization, coprecipitation, solvent extraction, etc. The evaporation crystallization and the coprecipitation are only suitable for low lithium-magnesium ratio, and a large amount of organic solvent is needed for solvent extraction, so that the method not only causes harm to the environment, but also has an erosion effect on equipment, and is difficult to industrialize. The ion exchange adsorption has the advantages of high selectivity, economy, environmental protection, regeneration and cyclic utilization and the like, and has wide prospect in the aspect of liquid lithium extraction.

The lithium ion sieve type adsorbent mainly comprises manganese system and titanium system. Manganese-based lithium ion sieves were the earliest studied and are the most studied lithium ion adsorbents, but the dissolution loss of manganese makes them difficult to recycle. The metatitanic acid type lithium ion sieve adsorbent has more researches in recent years due to the advantages of stable structure, large theoretical adsorption capacity and the like. However, they are relatively late to study and are currently still under the exploratory stage of synthesis.

The metatitanic acid type lithium ion sieve may be prepared by hydrothermal synthesis, sol-gel method, solid phase method, etc. Wherein, the hydrothermal synthesis method has complex synthesis and high cost and is difficult to realize industrialization. The sol-gel method is influenced by more preparation parameters, has low repetition rate, and has the problems of long synthesis period, high cost and the like. Compared with the high-temperature solid-phase method, the method has obvious advantages, and the synthesis process is simple and easy to industrialize. In patent CN101944600A, a lithium source and a titanium source are mixed by ball milling, and then a lithium ion sieve precursor Li is prepared by adopting a high-temperature solid-phase roasting method₂TiO₃The dissolution loss of the obtained lithium ion sieve is less than 1 percent, and the adsorption capacity is more than 14 mg/g; in the patent CN101157476A, self-made one-dimensional nano titanium dioxide is mixed with a lithium source and calcined to obtain a Li-Ti-O ternary oxide, and the Li-Ti-O ternary oxide is treated by an inorganic acid to obtain a titanium dioxide lithium ion sieve with better selectivity; yan Schwann et al uses rutile titanium dioxide as titanium source, and is synthesized by high-temp. solid-phase method, and its adsorption capacity is 29.15mg/g (Yan Schwann, Huangshihua. granular titanium dioxide exchanger development and lithium extraction from bittern]Ion exchange and adsorption, 1994, (3): 219-; respectively using TiO for face brightness and the like₂With Li₂CO₃Lithium ion sieves were synthesized by solid phase reaction for lithium and titanium sources and found to have a concentration of 5g/L of Li in LiOH and LiCl configurations⁺Research on preparation of novel lithium adsorbent with adsorption capacity of 32.29mg/g in solution [ J]Inorganic salt industry, 2014, 46(2): 38). The solid phase method has the defects that the mass transfer of the solid phase reaction is difficult to control, the complete and uniform mixing is difficult to ensure, and the contact state of reactants and whether the reaction process is sufficient or not or the particle size range of the product is overlarge are influenced by the mixing mode, the calcination temperature, the calcination time and the like of the reactants.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a synthesis method of a lithium extraction adsorbent, which is characterized in that a lithium source is dissolved in a solvent containing a certain amount of additives, then a titanium source is added to form a solid-liquid mixed state, slurry is dried, and the obtained precursor powder is regular in calcined morphology and uniform in particle size, so that the problems that solid-phase reaction mass transfer is difficult to control and complete and uniform mixing is difficult to ensure in solid-phase synthesis can be effectively solved.

The technical scheme is as follows: the invention relates to a synthesis method of a lithium extraction adsorbent, which comprises the following steps: adding the additive A into the solvent B, adding the lithium source C into the solvent B, dissolving the lithium source C, and stirring the mixture according to the proportion of Li: the molar ratio of Ti elements is 1.6-2.8: 1 adding a titanium source D, mixing to form slurry, continuously stirring for 0.5-48 h, and then drying the slurry to obtain solid powder; calcining the obtained solid powder to prepare lithium ion sieve adsorbent precursor Li₂TiO₃Precursor Li₂TiO₃Acid washing and lithium removing are carried out for 0.15-72H at the temperature of 20-90 ℃ to obtain metatitanic acid type lithium ion sieve adsorbent H₂TiO₃。

Further, the additive A is one or a combination of more than two of sodium hexametaphosphate, polyethylene glycol, ethyl cellulose, terpineol, a silane coupling agent, cetyl trimethyl ammonium bromide, polyvinylpyrrolidone, sodium dodecyl benzene sulfonate and polyacrylate.

Further, the mass content of the additive A is 0-20%.

Further, the solvent B is one or a combination of more than two of water, methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, acetone, butanol, ethyl acetate, cyclohexane and n-octane.

Further, the lithium source C is one or the combination of more than two of lithium hydroxide, lithium sulfate, lithium chloride, lithium acetate, lithium propionate, lithium nitrate, lithium hydroxide monohydrate, lithium acetate dihydrate and lithium oxalate.

Further, the titanium source D is one or the combination of more than two of anatase type titanium dioxide, rutile type titanium dioxide and brookite type titanium dioxide; the liquid-solid ratio of the solvent B to the titanium source D is 10-200 mL/g.

Further, the drying treatment mode is spray drying, airflow drying, flash evaporation drying or vacuum conduction drying.

Further, in the calcining process, the temperature is raised to 550-950 ℃ at the temperature rise rate of 1-10 ℃/min, and the temperature is kept for 1-72 hours.

Further, the acid used for acid elution of lithium is one or a combination of two or more of hydrochloric acid, sulfuric acid, nitric acid, sulfurous acid, hypochlorous acid, malonic acid, formic acid, acetic acid, propionic acid, citric acid and boric acid.

Further, the concentration of acid in the acid-eluted lithium is 0.01-1 mol/L, and the using amount of the acid is 0.5-50 g/L.

Has the advantages that:

(1) the lithium source is dissolved into a solvent containing a certain amount of additive and is mixed with the titanium source to form slurry, so that the lithium source and the titanium source form a solid-liquid mixed state, and the phenomenon that solid particles are difficult to mix uniformly in a solid-phase synthesis method is effectively improved;

(2) the slurry is dried, so that the raw materials are quickly dried and uniformly mixed, the particle size of the lithium ion sieve precursor obtained by calcining the obtained solid powder is uniform, and the agglomeration phenomenon in the synthesis process is remarkably reduced; metatitanic acid type lithium ion sieve H obtained after acid elution of lithium₂TiO₃The adsorption capacity is large, the selectivity is high, and the structure is stable;

(3) metatitanic acid type lithium ion sieve H prepared by the invention₂TiO₃The preparation process is simple, the operation and control are easy, and the large-scale production is easy to realize.

Drawings

FIG. 1 shows the adsorbent precursor Li of metatitanic acid type lithium ion sieve prepared in example 1₂TiO₃And lithium ion sieve adsorbent H₂TiO₃X-ray diffraction patterns of (a);

FIG. 2 shows the adsorbent precursor Li of metatitanic acid type lithium ion sieve prepared in example 1₂TiO₃And lithium ion sieve adsorbent H₂TiO₃An FTIR spectrum of (a);

FIG. 3 shows the adsorbent precursor Li of metatitanic acid type lithium ion sieve prepared in example 1₂TiO₃And lithium ion sieve adsorbent H₂TiO₃SEM image of (d).

Detailed Description

The invention is further described below with reference to the following figures and examples:

the instrument comprises the following steps: XRD: MiniFlex600 japan, scan range: 5-80 °, step size 0.02, scanning speed: 10 degrees/min, the scanning voltage is 40kV, and the current is 15 mA; FTIR: nicolet8700 nyoko corporation, usa; SEM: s4800, hitachi, japan; ICP-OES: optima 7000DV, Perkin-Elmer, USA.

Example 1

1. 6.1835g of lithium hydroxide monohydrate is dissolved in 100ml of aqueous solution containing 5 percent of hexadecyl trimethyl ammonium bromide, 4.0338g (the molar ratio of Li to Ti is 2.80:1) of anatase titanium dioxide is added into the aqueous solution under the stirring state, the stirring is continued for 24 hours, and the obtained slurry is subjected to spray drying under the stirring state at the feeding rate of 5ml/min and the spraying temperature of 120 ℃ to obtain solid powder;

2. heating the obtained solid powder to 700 ℃ at a speed of 5 ℃/min in a muffle furnace, and calcining for 72h to obtain a metatitanic acid type lithium ion sieve precursor Li₂TiO₃；

3. Mixing the precursor Li₂TiO₃Adding the powder into 0.3mol/L hydrochloric acid solution (solid-to-liquid ratio is 6g/L), magnetically stirring at 50 deg.C for 6H to remove lithium, filtering, washing, and drying to obtain metatitanic acid type lithium ion sieve adsorbent H₂TiO₃；

4. Adding the ionic sieve into a solution with the pH of 10 and the lithium concentration of 500mg/L, and magnetically stirring at 35 ℃ for 12 hours, wherein the adsorption capacity is 37 mg/g;

5. precursor Li₂TiO₃The XRD pattern of (A) is shown in figure 1, the FTIR pattern is shown in a in figure 2, and the SEM pattern is shown in a, b in figure 3; ion sieve H₂TiO₃The XRD pattern of (A) is shown in fig. 1 b, the FTIR pattern is shown in fig. 2 b, and the SEM pattern is shown in fig. 3 c, d. It can be seen from FIG. 1 that the crystal structure of the powder was changed slightly before and after the acid-washing for lithium removal, because the hydrogen ions were ion-exchanged with the lithium ions in the crystal, replacing the lithium ions in the crystal. From the precursor Li of FIG. 2₂TiO₃And ion sieve H₂TiO₃The FTIR spectrum of (5) shows H after acid washing₂TiO₃At 3489cm^-1Has a narrow peak of⁺/Li⁺Exchange-related OH stretching vibrations not involved in interactions with other oxygen-hydrogen groups, 3134cm^-1And 1632cm^-1Adsorbed water having a broad peak of hydrogen bondingStretching and bending vibration of the OH group. As can be seen from FIG. 3, Li before pickling₂TiO₃The surface of the pickling solution is rough after pickling, obvious pickling traces are formed, the appearance before pickling is still maintained, and the phenomenon of structural collapse is avoided.

Example 2

1. 8.2440g of lithium acetate dihydrate is dissolved in 80ml of absolute ethyl alcohol, 4.0338g of rutile type titanium dioxide (the molar ratio of Li to Ti is 1.60:1) is added into the anhydrous ethyl alcohol under the stirring state, the stirring is continued for 0.5h, and the obtained slurry is subjected to flash evaporation and drying under the stirring state at the feeding rate of 3ml/min and the air inlet temperature of 110 ℃ to obtain solid powder;

2. heating the obtained solid powder in a muffle furnace at 1 ℃/min to 550 ℃ to calcine for 12h to obtain a metatitanic acid type lithium ion sieve precursor Li₂TiO₃；

3. Mixing the precursor Li₂TiO₃Adding the powder into 0.01mol/L hydrochloric acid solution (solid-to-liquid ratio is 0.5g/L), magnetically stirring at 90 deg.C for 8H to remove lithium, filtering, washing, and drying to obtain metatitanic acid type lithium ion sieve adsorbent H₂TiO₃；

4. The ionic sieve was added to a solution of pH 11 and lithium concentration 1g/L, and the mixture was magnetically stirred at 55 ℃ for 12 hours, giving an adsorbed amount of 39 mg/g.

Example 3

1. 4.4794g of lithium chloride is dissolved in 800ml of aqueous solution containing 20 percent of polyvinylpyrrolidone, 4.0338g of rutile type titanium dioxide (the molar ratio of Li to Ti is 2.05:1) is added into the aqueous solution under the stirring state, the stirring is continued for 48 hours, and the obtained slurry is heated by steam under the stirring state at the feeding rate of 20ml/min, the vacuum degree of 60kPa and the shaft rotating speed of 10rpm for vacuum drying to obtain solid powder;

2. heating the obtained powder in a muffle furnace at 5 ℃/min to 800 ℃ for calcining for 9h to obtain a metatitanic acid type lithium ion sieve precursor Li₂TiO₃；

3. Mixing the precursor Li₂TiO₃Adding the powder into 1mol/L nitric acid solution (solid-to-liquid ratio is 50g/L), magnetically stirring at 45 deg.C for 0.15h to remove lithium, filtering, washing,drying to obtain metatitanic acid type lithium ion sieve adsorbent H₂TiO₃；

4. The ionic sieve is added into a solution with pH of 10 and lithium concentration of 200mg/L, and the solution is magnetically stirred for 12 hours at 35 ℃ and the adsorption capacity is 33 mg/g.

Example 4

1. 4.6030g of lithium chloride is dissolved in 40ml (70%) of ethylene glycol solution, 2.0169g of rutile type titanium dioxide and anatase type titanium dioxide (the molar ratio of Li to Ti is 2.15:1) are respectively added into the solution under the stirring state, the stirring is continued for 10 hours, and the obtained slurry is subjected to air flow drying under the stirring state at the feeding rate of 1ml/min and the air flow temperature of 120 ℃ to obtain solid powder;

2. heating the obtained solid powder to 950 ℃ at the speed of 10 ℃/min in a muffle furnace, and calcining for 1h to obtain a metatitanic acid type lithium ion sieve precursor Li₂TiO₃；

3. Mixing Li₂TiO₃Adding the powder into 0.05mol/L hydrochloric acid solution (solid-to-liquid ratio is 2g/L), magnetically stirring at 20 deg.C for 72H to remove lithium, filtering, washing, and drying to obtain metatitanic acid type lithium ion sieve adsorbent H₂TiO₃；

4. Weighing 1g of lithium ion sieve adsorbent H₂TiO₃Adding 1L of a solution containing Li⁺，Na⁺，K⁺,Ca²⁺，Mg²⁺The adsorption results of the lithium ion sieve on each metal ion are shown in Table 1, wherein the lithium ion sieve is magnetically stirred for 24 hours at the temperature of 35 ℃.

TABLE 1H₂TiO₃Adsorption selectivity of

Claims

1. A synthesis method of a lithium extraction adsorbent is characterized in that the synthesis process comprises the following steps: adding the additive A into the solvent B, adding the lithium source C into the solvent B, dissolving the lithium source C, and stirring the mixture according to the proportion of Li: the molar ratio of Ti elements is 1.6-2.8: 1 adding a titanium source D, mixing to form slurry, continuously stirring for 0.5-48 h, and then drying the slurry to obtain solid powder(ii) a Calcining the obtained solid powder to prepare lithium ion sieve adsorbent precursor Li₂TiO₃Precursor Li₂TiO₃Acid washing and lithium removing are carried out for 0.15-72H at the temperature of 20-90 ℃ to obtain metatitanic acid type lithium ion sieve adsorbent H₂TiO₃。

2. The synthesis method of the lithium extraction adsorbent according to claim 1, wherein the synthesis method comprises the following steps: the additive A is one or the combination of more than two of sodium hexametaphosphate, polyethylene glycol, ethyl cellulose, terpineol, a silane coupling agent, cetyl trimethyl ammonium bromide, polyvinylpyrrolidone, sodium dodecyl benzene sulfonate and polyacrylate.

3. The synthesis method of the lithium extraction adsorbent according to claim 1, wherein the synthesis method comprises the following steps: the mass content of the additive A is 0-20%.

4. The synthesis method of the lithium extraction adsorbent according to claim 1, wherein the synthesis method comprises the following steps: the solvent B is one or the combination of more than two of water, methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, acetone, butanol, ethyl acetate, cyclohexane and n-octane.

5. The synthesis method of the lithium extraction adsorbent according to claim 1, wherein the synthesis method comprises the following steps: the lithium source C is one or the combination of more than two of lithium hydroxide, lithium sulfate, lithium chloride, lithium acetate, lithium propionate, lithium nitrate, lithium hydroxide monohydrate, lithium acetate dihydrate and lithium oxalate.

6. The synthesis method of the lithium extraction adsorbent according to claim 1, wherein the synthesis method comprises the following steps: the titanium source D is one or the combination of more than two of anatase titanium dioxide, rutile titanium dioxide and brookite titanium dioxide; the liquid-solid ratio of the solvent B to the titanium source D is 10-200 mL/g.

7. The synthesis method of the lithium extraction adsorbent according to claim 1, wherein the synthesis method comprises the following steps: the drying treatment mode is spray drying, air flow drying, flash evaporation drying or vacuum conduction drying.

8. The synthesis method of the lithium extraction adsorbent according to claim 1, wherein the synthesis method comprises the following steps: in the calcining process, the temperature is raised to 550-950 ℃ at the heating rate of 1-10 ℃/min, and the temperature is kept for 1-72 h.

9. The synthesis method of the lithium extraction adsorbent according to claim 1, wherein the synthesis method comprises the following steps: the acid used for eluting the lithium by the acid is one or the combination of more than two of hydrochloric acid, sulfuric acid, nitric acid, sulfurous acid, hypochlorous acid, malonic acid, formic acid, acetic acid, propionic acid, citric acid and boric acid.

10. The method for synthesizing the lithium extraction adsorbent according to claim 9, wherein the method comprises the following steps: the concentration of acid in the acid-eluted lithium is 0.01-1 mol/L, and the using amount of the acid is 0.5-50 g/L.